Heat exchanger



Feb. 27, 1934. LIGHT 1,949,127

HEAT EXCHANGER Filed Feb. 20, 1932 Gttornegs Patented Feb. 2?, 1934 ni rit HEAT EXCHANGER Albert '1. Light, Canton, @hio, assignor to York Ice Machinery ilorporation, York, Pa, a corporation of Delaware Application February 20, 1932. Serial No. 594,253

6 Glairns.

The present invention relates to heat exchangers for milk and other liquids, especially that type of exchanger in which the liquid trickles by gravity over a plurality of superposed horizontal tubes through which a fluid cooling or heating medium is circulated.

More particularly, the invention pertains to inclined supporting lugs for the horizontal tubes, the lugs being arranged to prevent the liquid from coming in contact with the surfaces of other supporting elements and being coated with rustproof metal whereby danger of contamination is obviated.

It is well recognized that dairy equipment, particularly milk coolers, must be substantially free of such joints and corners that no surfaces in the path of the milk will be susceptible of rust or accumulation of foreign matter thereon. Means have been devised to inhibit, as far as possible, the mingling of milk and condensates, but usually these remedial means have been applied at the sacrifice of cooling surface.

In the present invention, the supports are so designed that milk is caused to flow over surfaces on which no rust can form, corners tending to accumulate foreign matter are eliminated and maximum cooling surface is available for heat exchange. The invention will be more fully understood from the following description in which reference is made to the appended drawing.

Fig. 1 is a front elevation of a milk cooler in which the present invention is embodied;

Fig. 2 is a partial elevation of the cooler showing one form of return bend and support therefor;

Fig. 3 is a partial top view of the section illustrated in Fig. 2;

Fig. 4 is a partial elevation of a modified form of bend and support; and

Fig. 5 is a top view of the bend and support shown in Fig. i.

The invention is applicable to exchangers for cooling or heating, but for purposes of illustration, a milk cooler is described. The cooler comprises the usual supply and receiver troughs 11 and 12, respectively, supported by brackets 13 and standards 14. Interposed between the troughs is a cooling unit 15 consisting of a plurality of horizontal tubes 16 arranged one above the other and connected by return bends 17 to form a continuous passage for brine or other cooling mediiun from inlet 18 to outlet 19.

The return bends and tubes are made rustproof by forming them from or plating them with a suitable metal, such as non-corrosive ferrous alloys or nickel silver, and are welded to each other in such a manner that, when assembled, no corrosive metal is exposed to mill; or other liquid flowing thereover. A fin 2G is welded or otherwise secured to each tube and return bend along the lower sides thereof, as is usual in this type of cooler.

To each return bend there is Welded a noncorrcsive metal lug 21, the latter being secured angularly to the bend, that is, inclined upwardly from the bend, as shown in the drawing. The welded joint is scraped smooth and at the upper side of the joint, indicated at 22, a fillet obviates any pocketing of foreign matter and facilitates cleaning.

Each of the supporting-lugs is provided with a reduced horizontal portion 23 adapted to be Welded openings 2% in supporting side plate 25 at each end of the cooler, the plates having a length approximately equal to the height of the cooling unit and accommodating all of the lugs. When the unit is relatively high, however, two or more vertically aligned plates may be used. Plates 25 each have a lug 26 near the upper end thereof fitting in brackets 2'7 also secured to standards 1 The joints between lugs 21 and plates 25 are smoothed and filleted similarly to those between the lugs and return bends. Plates 25 are either cast from or plated with a noncorrosive metal to prevent the formation of rust thereon.

The return bends 17' illustrated in Fig. 4 are curved, as distinguished from the mitered bends shown in Fig. 2, but the manner in which the lugs are attached thereto is the same. The ends, a

of the ins are curved as shown at 28 to conform with the curvature of the next lower return bend and thereby minimize the gap between the fin and the curved surface of the bend to prevent splashing of the milk as it falls from one bend to another.

In practice, the return bends are disposed within the curtain of liquid falling from feed trough 11. This is possible due to the position and inclination of supporting lugs 21 which are in vertical alignment with the ends of the troughs and direct diverted milk back to the cooling unit. In this way the entire surface of the unit is available ior heat exchange. It is further apparent that no part of the unit is exposed to the surthat joints susceptible to rust are eliminated, cleanliness promoted, and all available cooling parts be extended to any of those suitable for the purposes described.

What is claimed is:-

1. In a heat exchange unit of the class described, a plurality of superposed horizontal tubes; curved return bends connecting the tubes to form a continuous passage; and a fin on the lower side of each tube extending to the ends of the return bends, said fins being curved at their ends to conform to the curvature of the next lower return bend.

2. In a heat exchanger of the trickier type, the combination of a heat exchange unit formed with an internal passage for heat exchanging fluid; means for producing a descending trickling flow of liquid to and over the external surface of said unit; and at least one supporting member for said unit inclined upward from said unit and outward beyond the path of descending trickling flow of liquid, whereby liquid contacting said supv porting member will tend to flow by gravity to said unit.

3. In a heat exchanger of the trickler type, the combination of a plurality of superposed substan tially horizontal tubes; return bends connecting successive tubes to form a continuous passage for heat exchanging. fluid, the tubes and said bends being in the path of trickling flow; sustaining means adjacent said bends but outside the path of trickling flow; and supporting lugs on certain of said bends and connected to said sustaining means, said lugs being inclined upwardly from the bends to preclude gravity flow from the bends to the-sustaining means.

4. In a heat exchanger of the trickler type, a plurality of superposed substantially horizontal tubes; return bends connecting successive tubes to form a passage for heat exchanging fluid, said tubes and bends being located in the path of trickling flow; a sustaining plate at opposite ends of the tubes adjacent the return bends and outside the path of trickling flow; and supporting lugs on certain return bends, said lugs being inclined upward from their respective bends to a point of connection with the plates, the inclination of the lugs serving to preclude flow of trickling liquid along the lugs to the plates.

5. In a heat exchanger of the trickler type, the combination of a heat exchanging unit made up of tubular runs connected by bends to form a passage for heat exchanging fluid, said unit as a Whole being mounted in the path of trickling flow; sustaining means for said unit adjacent said bends but outside the path of trickling flow; and means for connecting said unit with said sustaining means, comprising lugs integral with said bends and with said sustaining means, each such lug being inclined upward from the bend to the sustaining means to resist flow from the unit to the sustaining means.

6. In a heat exchanger of the trickler type, a plurality of superposed substantially horizontal tubes; bends connecting the tubes to form a passage for a heat exchanging fluid; a supply trough mounted above said tubes and arranged to deliv er a trickling flow of liquid to said tubes and bends; a receiving trough beneath said tubes and bends; sustaining means located beyond the ends of the first-named trough; and lugs connecting ALBERT T. LIGHT. 

